IMPROVEMENTS IN OR RELATING TO PALLETS

Abstract: An impact absorber element (13) to provide a leading edge of a pallet (10) intended to be engaged, in use, by lifting forks is moulded of resilient material as a honeycomb-like board or plank having parallel front and rear faces in the form of first ribs (14) with further first ribs therebetween and parallel thereto. The first ribs (14) are arranged in three zones, the spacing apart of ribs in the zone adjacent the front face being smallest, and increasing in subsequent zones. In each zone there are further ribs (15) which cross the first ribs at an angle other than 90 DEG and spaced, parallel straight connecting members (16) lie normal to the first ribs. The arrangement of ribs ensures the necessary deflection characteristics should the element be hit by the lifting forks or associated lift truck, in use.

Description: IMPROVEMENTS IN OR RELATING TO PALLETS This invention relates generally to pallets which are designed to be engaged by lifting forks of handling means and are for carrying items thereon to be moved from one location to another upon operation of the handling means. Conventionally such a pallet for a lift truck is constructed of wood and is normally in the form of a square or rectangular construction comprising several wooden boards laid laterally across the upper and lower sides respectively of spaced apart parallel spacers, the outer two of which form respective sides of the pallet. However manoeuvring lift truck forks into their intended engagement position between the upper and lower boards of the pallet can often result in the forks hitting the (upper) leading edge of the pallet and the wood splintering. In time the damage at said leading edge can be such that the pallet can no longer properly bear the weight of the item which it is intended to support. This type of damage may also occur by the lift truck itself hitting the pallet during driving of the truck in an area where the pallet is stacked. An object of the invention is to mitigate or overcome this problem. According to a first aspect of the invention there is provided an impact absorber element to provide a leading edge of a pallet, which pallet is intended to be engaged, in use, by lifting forks, the element having a front face which, when the element forms part of the pallet, in use, constitutes said leading edge, and a rear face, there being between said faces first ribs, which are parallel or substantially parallel to said front face, and further ribs, which cross said first ribs, the first ribs being arranged in at least two zones, in one of which the spacing between the ribs is less than in another of which, said one zone extending from said front face. Preferably said further ribs cross said first ribs at an angle greater or less than 90° and conveniently said angle is different in said at least two zones. Desirably the element is of resilient material such as plastics material, and is for example produced by moulding. Advantageously the moulding produces locations for fixing the element to form part of the pallet by screws, nails or the like. According to a second aspect of the invention there is provided a pallet adapted for engagement by lifting forks, said pallet having a leading edge formed by a unitary element of resilient material. Said element is preferably parallel to other members forming at least part of an upper surface of the pallet and said lifting forks are, in use, received by the pallet at said leading edge. Accordingly said leading edge of the pallet can absorb impact energy by virtue of the deformation characteristics of the element so that any contact with said edge is deflected without damage thereto. Preferably the pallet has a further alternative leading edge opposite from and parallel to said leading edge also formed by a unitary element of resilient material so that the pallet can be. used in either of two orientations relative to the lifting forks. According to a third aspect of the invention there is provided a pallet adapted at a leading edge thereof for engagement by lifting forks, an impact absorber element as hereinbefore defined forming part of the pallet and defining said leading edge. Desirably a further such impact absorber element defines a further alternative leading edge opposite from and parallel to said leading edge. The invention will now be defined, by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic, perspective view of a pallet of one aspect of the invention; Figure 2 is a diagrammatic plan view of an impact absorber element of another aspect of the invention, and Figure 3 is a diagram of annular contact of a cylindrical container on a pallet. Figure 1 shows a pallet 10 constructed in accordance with the present invention. The pallet would in fact be of conventional form apart from the replacement of the two wooden planks or boards at the opposite longitudinal top edges of the pallet as shown in Figure 1. Thus as far as the conventional part of the pallet construction is concerned, the pallet would have its upper and lower surfaces formed by laterally extending wooden planks or boards 1 1 , the surfaces being spaced one on top of the other by square or rectangular wooden blocks 12 to which the planks or boards are secured and extend normally. The two opposite outermost blocks 12 form sides of the pallet. In this way the pallet is generally hollow between its surfaces, the blocks defining an appropriate opening for reception of a pair of forks of a conventional forklift truck or the like so that the pallet can be received wholly on the forks for movement by the truck in a conventional manner. The pallet can be rectangular or square and the planks or boards would normally be shaped accordingly. Other pallet shapes are however possible. Instead of being with their longitudinal edges in contact, the planks or boards 11 could be spaced apart. To prevent damage such as splintering to the wooden board at the leading edge of the pallet, normally defined by the upper front board, the present invention, in a preferred embodiment, replaces the first plank on each of the top ends of the pallet with an impact absorber element 13, as shown in Figure 1. In the example shown, the two opposite longitudinal end edges of the pallets are provided with this replacement impact absorber element 13, so that the forks can enter the pallet at either of its open ends with the danger of damage to the top plank at that end now having been removed. Alternatively however, the element 13 could of course be provided at only one of the open ends of the pallet or at the only open end. Thus the pallet constructed in accordance with an embodiment of the invention has a composite top surface with two such elements 13, one at each leading edge, and wooden planks or plywood in the space between the two elements. The element 13 is preferably a moulding and is of resilient material, for example of thermo-plastics material so that, as will be described, it is able to absorb any impact energy without permanent deformation, at least as far as normal impacts are concerned. It preferably is of the equivalent length and depth to the plank it replaces. Although normally only having a width of one plank, it could replace more than one if desired. The element 13 is of generally hollow honeycomb form being made up of a multiplicity of straight, flat parallel, narrow strips 14 forming first ribs parallel to the two longer sides of the element, (which themselves are formed by strips 14), but lying laterally to the direction in which the lifting forks move relative to the element 13. Each first rib is, for example, 19mm deep and about 3mm wide. The length of the first ribs can be varied as required for any particular size of pallet. As can be seen schematically and diagrammatically from Figure 2, where an element is shown in more detail than in Figure 1 , the spacing between the ribs is not constant in that the first ribs are divided into at least two, and in the embodiment shown three, different zones, with the spacing between adjacent ribs in one zone being different from such spacing in another zone. In Figure 2 these three zones are marked 'A', 'B' and 'C. The outermost first rib in zone 'A' would normally form the leading edge of the pallet, whilst the outermost first rib of zone 'C would be disposed inwards in the pallet and adjacent a wooden board or plank. It can be seen that, in the embodiment illustrated, the first eight of the first ribs are relatively closely packed whereas the spacing then increases for approximately the next three of the first ribs, which forms zone 'B', with the spacing for the remaining ribs being further increased to form the ribs in zone 'C. The difference in pitch which is thus provided, particularly between the front of the leading edge and the rearmost edge defined by the moulding, is to ensure that when a product is carried by the pallet, for example a beer keg or similar circular section item, adequate support is given at the very front of the leading edge. In one embodiment of the invention, representing an extreme form of the element 13, the spacing between each pair of strips increases in a direction away from the leading edge, so that the first and second strips form a first zone, the second and third strips form a second zone, and so on. The spacing can increase constantly or non-constantly as required. As well as the 'lateral' ribs formed by the strips 14, the moulding also comprises substantially identical strips 15 which form second ribs, these being disposed so as to cross the first ribs at an acute or obtuse angle. Although the strips 15 could have the same depth as the strips 14, they are, in one embodiment, of slightly less depth so that they are recessed on both sides of the element from the respective planes containing the sides of the strips 14. As can be seen from Figure 2 the second ribs, like the first ribs can be zoned. However in the embodiment of Figure 2 these second ribs are formed only in two zones rather than three. It will be apparent that the second ribs in zone 'A' are denser and cross the first ribs at a steeper angle than do the second ribs in zones 'B' and 'C. Again it is preferable for there to be denser ribbing in zone 'A' which forms the outer area of support for circular barrels and the like carried on a pallet, but is not essential and any of many different combinations of second ribbing can be used with the element 13. It is however important to provide second ribbing in order that the element has the necessary deformation characteristics so that if the forks of the forklift truck, or indeed the truck itself, hit the front edge of the element 13 the impact is deflected in a known way with the impact energy being absorbed by the resiliency of the material which thereafter assumes its underformed shape without lasting damage. The cross bracing provided by the second ribs provides stiffening. Instead of there being second ribs inclined in opposite directions, so as to cross each other, the second ribs could be inclined in one direction only without such crossing. The provision, arrangement and form of zones for the first and second ribs can be selected as required. For example with the first ribs, the pitch and number of first ribs in zone 'A' could be decided and zones 'B' and 'C be formed by doubling the pitch and doubling the number of ribs in the zone so that there would be twice as many ribs in zone 'B' as in zone 'A', and twice as many ribs in zone 'C as in zone 'B', with the pitch in zone 'C being twice that in zone 'B'. Alternatively the arrangement of first ribs could be in the approximate relationship determined by the first quadrant of a sinusoidal curve. In this regard, Figure 3 shows the peripheral contact area typical of a keg or other type of cylindrical container 17 on a pallet. By regarding the boundary lines of each zone as being analogous to the strips 14, between zones 'A', 'B', 'C etc., it can be seen that zone one accounts for 24.8% of the peripheral contact area and zone two for 6.53%, the strips in each zone thus being spaced to equalise the loading on each rib. Preferably the moulding is also formed with a number of straight connector members 16 (Figure 2) which lie at 90° to the first ribs and extend through both the first and second ribs, although as will be described, along the length of the connector members the second ribs may be absent or only present at spaced intervals, given that each connector member provides a certain amount of bracing. In the example shown in Figure 2 members 16 are identified at opposite sides of, and parallel to, a centre line of the moulding and as shown, further connector members could be formed at the extreme opposite sides of the element 13. Although each member can be of any appropriate cross-section, in one embodiment the member 16 could be of generally aerofoil cross- section, or in the form of a flattened oval. Other straight connector members could also be provided in the moulding parallel to the members 16 along the length of the moulding. These members add material to the element. The members preferably extend the whole distance between the front and rear faces of the element. As is evident from Figure 2, the second ribs cross the first ribs in two directions substantially at 90° to one another, forming diamond or square shapes. As shown these generally mutually perpendicular second ribs also extend across the member 16. However, if required the second ribs could be omitted across the member 16 or only present in a spaced arrangement along the length of the member 16. As shown in Figure 2, the second ribs can cross in a different manner along a member 16 from elsewhere in a zone of the element. Finally, as far as the moulding is concerned, it is provided with means 18 for connecting the element 13 to the remainder of the pallet by screws, nails or other fixing elements. In one embodiment holes for receiving fixing elements, the holes being countersunk at both of their ends, are provided through the moulding, each hole being formed at the intersection of a first rib and a pair of mutually perpendicular second ribs, so that each hole has four second ribs and two first ribs radiating from it. In particular these holes are formed to lie over the blocks 12 and can be through a member 16. Alternatively the or each element 13 could be fixed to the remainder of a pallet 10 by other means. The members 16, as solid membranes, are particularly suitable for receiving nails to fix the element 13, the nails being disposed at any suitable position(s) along a member 16. An element 13 can be produced to fit any required size of pallet. However a typical size of element 13 would be 1320mm long, 200mm wide and 19mm deep. Accordingly the present invention, which relates both to an impact absorber element and also a pallet having its leading edge formed of resilient material, overcomes the problem of leading edge damage with wooden pallets, and as defined in one aspect of the invention, the provision of the element 13 provides adequate support at the very front of the leading edge when the pallet is used particularly with circular items such as kegs and the like. Instead of the element forming a leading edge at the end where the lifting forks engage the pallet, it could instead form a leading edge only at one or both of the sides at 90° thereto, thereby protecting the pallet only from impacts by fork lift trucks at said side or sides. Instead of being part of a fork lift truck, the lifting forks can be part of a mechanical handling system, for example being arranged for up and down movement on a stationary mast or the like which is built into the system.

Claims: CLAIMS 1. An impact absorber element to provide a leading edge of a pallet, which pallet is intended to be engaged, in use, by lifting forks, the element having a front face which, when the element forms part of the pallet, in use, constitutes said leading edge, and a rear face, there being between said faces first ribs, which are parallel or substantially parallel to said front face, and further ribs, which cross said first ribs, the first ribs being arranged in at least two zones, in one of which the spacing between the ribs is less than in another of which, said one zone extending from said front face. 2. An element as claimed in Claim 1 ,. wherein said further ribs cross said first ribs at an angle greater or less than 90°. 3. An element as claimed in Claim 2, wherein some of further ribs cross the first ribs at an acute angle and are themselves crossed by others of the further ribs which cross the first ribs at an obtuse angle. 4. An element as claimed in Claim 3, wherein said some of the further ribs intersect with said others of the further ribs at 90° or substantially 90°. 5. An element as claimed in any one of Claims 1 to 4, wherein the angle at which a further rib crosses a first rib is different in said at least two zones. 6. An element as claimed in any one of Claims 1 to 5, wherein the further ribs are recessed relative to the respective outer surfaces of each first rib. 7. An element as claimed in any one of the preceding claims, wherein connecting members extend normal to the first ribs. 8. An element as claimed in Claim 7, wherein each connecting member extends from said front face to said rear face. 9. An element as claimed in Claim 7 or Claim 8, when dependent upon Claim 3, wherein the further ribs cross each other in a different arrangement at a connecting member from elsewhere in a zone. 10. An element as claimed in any one of the preceding claims, wherein the first ribs are spaced in each zone to equalise the loading, in use, on each rib, the loading on each zone being proportional to the peripheral contact area of a circular section container centred on said pallet, in use. 1 1. An element as claimed in any one of the preceding claims, which is produced of resilient material by moulding. 12. An element as claimed in Claim 1 1 , wherein formed in the moulding are locations for securing the element, in use, to a pallet frame to provide said leading edge of the pallet. 13. An element as claimed in any one of the preceding claims, which is of honeycomb form, being hollow between the first ribs and the further ribs. 14. A pallet incorporating an impact absorber element as claimed in any one of Claims 1 to 13, defining one of its leading edges. 15. A pallet as claimed in Claim 14, incorporating two such impact absorber elements defining opposite leading edges thereof respectively. 16. A pallet adapted for engagement by lifting forks, said pallet having a leading edge formed by a unitary element of resilient material. 17. A pallet as claimed in Claim 16, wherein the lifting forks are, in use, received in openings at a side of the pallet at which said leading edge is disposed. 18. A pallet as claimed in Claim 16 or Claim 17, wherein said unitary element is an impact absorber element as claimed in any one of Claims 1 to 13. 19. A pallet as claimed in Claim 18, incorporating two such impact absorber elements defining opposite leading edges thereof respectively. 20. A pallet as claimed in any one of Claims 16 to 19, wherein said element is parallel to other members forming at least part of an upper surface of the pallet.

Inventors: WHEATON CHRISTOPHER SIMON COUR, WHEATON, CHRISTOPHER, SIMON, COURTENAY
Applicants: KEG SERVICES LTD, KEG SERVICES LIMITED
Application year: 1994
Main classification: B65D19
IPC codes: B65D19